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rf filter

I'm working on a project and I want to block 5Mhz through 200Mhz so I can insert a new carrier. I've emailed a few companies and asked on-line, but so far... no luck..
I know it's not a regular filter that blocks the return, but if it works right.. could be a good size order. Any thoughts?

What it sounds like you are looking for is a highpass filter. You will have to remember that a filter has a curve, so frequencies just above the stop frequency range will also be affected. For example an ECHP 216/200 highpass filter will give you 50db of attenuation from 0-200mhz, but your first useful frequency will be 216mhz. Hope this helps.

Microwave Filter Company out of New York. They make custom bandstop filters and I used to use these for dropping adjacent channels from one market and adding new ones in their place, all at the RF level. It's not cheap.

Whatever filters you end up selecting, be sure to provide yourself enough cushion around the edge of the filter that you are not affecting your desired passthrough frequencies. No filter can give you sufficient attenuation and falloff immediately. Best to start with what you want to do and select a filter on that basis. If you need 200 MHz and up to pass cleanly, plan for a filter that blocks 5-180. If you need the full spectrum to 200mhz for something, plan to leave a few channels above that. At the risk of being another old rf guy, the reason that there is a custom filter to 200 MHz is that with a north American channel plan you are passing analog cable 23 and up (superband) while trapping out midband and highband (vhf 7-13). This was useful when sending analog cable from one market to another (via microwave or analog fiber) where you would reinsert local programming and premium channels. I would be very comfortable that that filter works exactly as described because they have been in production for decades.

Thank you everyone
I've attached an example of a capture for one filter I've looked at. it's not docsis 3.1 but uses qams like 2048 to deliver 1Gb in large condo or apartment buildings. thought was to still pass some video services if needed. but like most, streaming will be replacing current video services. I've been doing this way too long lol, I remember when ppv was done by calling the office